Hemostasis valves are used during some interventional procedures to minimize back bleeding and to prevent the introduction of air that may result in an embolism, while permitting the introduction of medicine and medical devices to blood vessels in a patient's circulatory system. For example, a hemostasis valve can be used to introduce wires, sheaths, catheters which may be equipped with balloons and lumens, and other elongate medical devices into a vein or artery. Example procedures include, but are not limited to, angiography, angioplasty and embolization procedures. In other examples, a hemostasis valve is used during a fluoroscopy procedure to introduce fluoroscopically identifiable materials, e.g., barium dye, to observe the patient's circulatory system. In some circumstances, interior portions of the hemostasis valve can be pressurized with liquid to prevent blood or gases from escaping.
Some hemostasis valves are y-shaped with three ports that are individually associated with an arm of the “y”. The ports are configured as input ports for accepting a medical device or a liquid, or as an exit port through which the medical device or liquid passes into the patient's circulatory system. Other commercially available hemostasis valves include additional arms, e.g., a double-y configuration, that has an additional port for introducing a medical device or liquids through the valve and into the patient. Hemostasis valves can include a variety of valve systems to control movement of liquids, medical devices, and so on in the valve. The valve systems typically include a primary valve, such as a three-way stopcock type valve, for a standard hemostasis valve, and a variety of seals or mechanism for controlling addition/removal of medical devices and fluids. One of the ports, for example, an inlet port that is often axially align with the outlet port, can include a “twist-lock” or “push-pull lock” to control introduction of or removal of a medical device from the patient. Some elongate medical devices used with hemostasis valves can be fed or withdrawn by manipulating one of these lock devices to lock or seal the valve and then to insert or withdraw the device to target where the medicine or device is located. For example, an access sheath (having one or more guide wires therein) may be fed through an inlet port into the valve for eventual insertion into a vein.
The sizes of the inlet ports for hemostasis valves vary based on different manufacturers. Thus, although the hemostasis valve can be a particular French size indicating how large the valve is, the internal components (especially the seal devices proximate to the inlet port(s)) can be sized and configured differently between various manufacturers.